A Canadian couple have decided to raise their 4-month-old baby to be "genderless" to protect its right to choose its own sex.

Kathy Witterick, 38, and David Stocker, 39, refuse to say whether their child Storm is male or female, the Toronto Star reports.

The couple say they want to spare the child the pressures of social norms. The only people who know the child's biological sex are 5-year-old brothers Jazz and Kio, a close family friend, and two midwives who delivered the baby.

"When the baby comes out, even the people who love you the most and know you intimately, the first question they ask is, 'Is it a boy or a girl?" Ms Witterick said.

The couple told friends their refusal to answer such questions was "a tribute to freedom in place of limitation" and a "stand-up to what the world could become in Storm's lifetime".

"If you really want to get to know someone, you don't ask what's between their legs," Mr Stocker said. "What we noticed is that parents make so many choices for their children. It's obnoxious."